yes , its a natural component of coral reefs. Corals feed on them as well as fish. Its a high protein organism, good for fighting disease and help aid in tissue repair.
IF its live you can put it in anytime. If its dead, I would add it sparinily as it will be metabolized by bacteria causing nitrates and phosphates build up.
Its a good idea to feed at night when corals expand their nemotsysts to feed. They are most active at that time, because zooplankton feed at night.
Good luck